Problems with my house guests! Please help!

See, I'm having a few friends over today. But I'm having some problems with them... You see, they're kind of... eccentric...
Okay, let's start with this first girl. She kinda reminds me of sexi_emo_girl... You see, she has a huge obsession with knives. It's always knives this, knives that! She brought her own knife when she came here! And a while ago, that bloodthirsty girl actually got sent to juvie for attacking a bunch of people with one! And now, I'm seriously worried she's gonna try to assault someone here or something if they give her the slightest provocation! Oh, and she LOVES the color red. She's always wearing it... and I don't even think I need to ask why...
Thank Lord, the 2nd guy is way easier. He's actually really nice. So much he is kind of a pushover... His favorite color is blue. Kinda suits him, huh? And he loves singing and roses... You get it, peaceful, artistic type.
The other one is this really cute, charming, popular girl. You know the type. She's like the queen of the world. Everybody loves her and she can charm most people into doing basically anything she wants. Her biggest flaw is her Thanatophobia (overly great fear of death). But hey, her life is so awesome, it kinda makes sense!
Finally, there are a couple of blond siblings. Brother and sister. Um... I didn't even invite them! Apparently, the popular girl did! When they came over at first, I almost kicked them out before she came to explain if it weren't for the big sister's stubborn insisting to stay. (The little brother isn't as stubborn as she is. He's more of a smart guy.) Oh, and... they were two of those who were attacked by the mad girl! So I think it's safe to say every time they're together, it's pretty akward.
Anyway, I'm freaking out, it's as crazy as Lewis Caroll's Wonderland or something over here... Please help already!